Betatron

ABSTRACT

A betatron comprising an electromagnet having a pair of opposing poles spaced adjacent one another and acting to transfer a magnetic flux in a zone therebetween, is provided with an acceleration vacuum vessel interposed between the poles. An injector is mounted internally of the vessel and the injector includes an electron emissive filament. A winding coil is connected to one of the poles and surrounds the flux zone. The filament is electrically coupled with the winding for being heated by electrical energy induced in the winding in response to the magnetic flux.

United States Patent Inventors Lev Martemianovich Ananiev ulitsa Lenina, 44, kv. 10; Yakov Semenovich Pekker, ulitsa Sovetskaya, 73, kv. 23; Vladimir Lukianovich Chakhlov, pereulok Zavodskoi, 8/1, kv. 8; Yakov Afanasievich Sharachin, poselok Sputnik, l5, kv. 22; Mikhail Mikhailovich Shtein, ulitsa Usova, 17, Kv. 8; Jury Pavlovich Yarushkin, ulitsa L. Tolstogo, 65, kv. 8, all of Tomsk,

U.S.S.R. Appl. No. 822,405 Filed May 7, 1969 Patented Oct. 19, 1971 BETATRON 6 Claims, 1 Drawing Fig.

US. Cl 328/237, 313/62, 315/57 Int. Cl H05h 11/00 Field of Search 313/62;

[56] References Cited UNITED STATES PATENTS 2,394,071 2/1946 Westendorp 328/229 2,546,484 3/1951 Wideroe 328/233 Primary Examiner-Raymond F. Hossfeld Attorney-Waters, Roditi, Schwartz & Nissen ABSTRACT: A betatron comprising an electromagnet having a pair of opposing poles spaced adjacent one another and acting to transfer a magnetic flux in a zone therebetween, is provided with an acceleration vacuum vessel interposed between the poles An injector is mounted internally of the vessel and the injector includes an electron emissive filament. A winding coil is connected to one of the poles and surrounds the flux zone. The filament is electrically coupled with the winding for being heated by electrical energy induced in the winding in response to the magnetic flux.

' BETATRON The present invention relates to magnetic induction electron accelerators or betatrons used for physical and biological studies, in flaw detection and medicine.

Known in the art are betatrons comprising an electromagnet with an acceleration vacuum vessel provided with an injection having an electron emissive heated filament (cf. U.S. Pat. No. 2,583,549, Class 313-62 ofFeb. 12, 1952).

In the known betatron the electron emissive filament is heated from an auxiliary filament transformer. Y

A disadvantage of this betatron is the presence of an auxiliary filament transformer which increases the size and weight of the betatron, thereby limiting the field of its application.

The present invention has for its object the provision of a betatron in which the electron emissive filament is heated not from an auxiliary filament transformer but from a device using a variable magnetic flux created by the betatron electromagnet and which has a small size and weight.

With these and other objects in view, the present invention resides in that in the betatron comprising an electromagnet with an acceleration vessel disposed between the electromagnet pole pieces and having an injector with an electron emissive filament, the filament winding, according to the present invention is placed within the electromagnet is such a way that it embraces the magnetic flux created by the electromagnet.

The invention will be better understood from the following description of an embodiment thereof, given by way of example with reference to the accompanying drawing which represents a cross-sectional view of a betatron according to the present invention.

The betatron comprises an electromagnet l creating an acceleration magnetic flux 1 which passes in a zone through an acceleration vacuum vessel 2 with an injector 3 mounted thereinside, which injector has an electron emissive filament 4 with voltage supply leads 5 and a winding 6 for heating said filament. The acceleration vacuum vessel 2 is disposed between pole 7 of the electromagnet I.

The voltage supply leads 5 of the filament 4 are connected to the filament winding 6. The winding 6 is placed within the electromagnet I in such a way that it embraces or surrounds the magnetic flux created by the electromagnet.

The betatron operates in the following manner.

When the electromagnet is connected to a power supply source, a variable magnetic flux I is created in the former. As a result, a variable voltage is induced in the filament winding 6, which ensures current flow through the circuit, this current causing filament heating and electron emission. Thereafter the electrons are accelerated by an eddy-current electric field induced by the magnetic flux.

The present invention is advantageous in that the filament 4 of the injector 3 is heated not from a separate filament transformer but from a winding embracing the magnetic flux of the betatron electromagnet. This makes it possible to dispense with the transformer magnetic structure, thereby reducing the weight of the betatron, which is particularly important with small-size portable betatrons in which the weight of the filament transformer amounts to 7-l0percent of the electromagnet weight.

While the present invention has been hereinbefore described with respect to a specific embodiment, it will be apparent that numerous modifications and variations are possible within the spirit and scope of the invention.

Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as disclosed in the appended claims.

What is claimed is:

l. A betatron comprising an electromagnet, said electromagnet including a pair of opposing poles spaced adjacent one another and acting to transfer a magnetic flux in a zone therebetween, an acceleration vacuum vessel interposed between said poles, an injector mounted internally of said vessel, said injector including an electron emissive filament, and

windin means connected to one of said ples and surroundmg the ux zone, said filament being elec rically coupled with said winding means for being heated by electrical energy induced in the latter in response to the magnetic flux.

2. A betatron as claimed in claim 1 wherein said electron emissive filament includes a pair of voltage supply leads extending externally of said vessel and electrically interconnecting said winding means and filament.

3. A betatron as claimed in claim 1, wherein said poles have respective tapered surfaces converging toward one another.

4. A betatron as claimed in claim 3, wherein the respective tapered surfaces terminate in respective flat central portions.

5. A betatron as claimed in claim 4 wherein said poles are of substantially identical configuration with respective tapered surfaces and fiat central portions coaxially spaced from one another.

6. A betatron as claimed in claim I wherein said winding means extends in a plane extending substantially tranversely of the direction of transfer of the magnetic flux. 

1. A betatron comprising an electromagnet, said electromagnet including a pair of opposing poles spaced adjacent one another and acting to transfer a magnetic flux in a zone therebetween, an acceleration vacuum vessel interposed between said poles, an injector mounted internally of said vessel, said injector including an electron emissive filament, and winding means connected to one of said poles and surrounding the flux zone, said filament being electrically coupled with said winding means for being heated by electrical energy induced in the latter in response to the magnetic flux.
 2. A betatron as claimed in claim 1 wherein said electron emissive filament includes a pair of voltage supply leads extending externally of said vessel and electrically interconnecting said winding means and filament.
 3. A betatron as claimed in claim 1, wherein said poles have respective tapered surfaces converging toward one another.
 4. A betatron as claimed in claim 3, wherein the respective tapered surfaces terminate in respective flat central portions.
 5. A betatron as claimed in claim 4 wherein said poles are of substantially identical configuration with respective tapered surfaces and flat central portions coaxially spaced from one another.
 6. A betatron as claimed in claim 1 wherein said winding means extends in a plane extending substantially tranversely of the direction of transfer of the magnetic flux. 